ClassicWeather offers clear weather widgets in 3 different sizes and colors. It also provides weather forecast in the dock and menu bar menu.

Features:

Current weather conditions
Forecast for 7 days
Forecast for next 12 hours
Forecast by the hour
Forecast in text format
Temperature in Fahrenheit or Celsius
Probability of precipitation
Rain/snow in mm/inch
Feels like temperature
Local time
Sunrise / sunset
Current phase of moon
Multiple cities
Current location (WiFi needed)
Weather in menu bar menu and dock menu
12-hour or 24-hour time format
3 widget designs, 4 sizes
2 modes (single window or widget)
Retina supported
And more

Additional features with Premium subscription ($1.49 per year):

Forecast for 10 days
Forecast for next 24(+) hours (scrollable)
Humidity
Wind speed and direction
Current condition on dock icon and menu bar
App in dock and/or menu bar